1. Field of the Invention
The present invention relates generally to the protection of printing media and the like. More particularly, the present invention relates to transparent, printed-sheet protection sleeves.
2. Description of the Related Art
An example of a prior art typical, transparent, printed-sheet protection sleeve is shown in FIG. 1. Such protectors are generally made of some type of acetate or Mylar film (Mylar is a registered trademark of E.I. duPont de Nemours & Co.).
The protector 11 is generally a single sheet 13 having parallel folds 15, 17.
One fold 17 is near an edge 19 of the sheet 13. Thus, that fold 17 forms a minor, or "sealing," flap 21.
The other fold 15 is positioned to form a major flap 29 so that when the sheet 13 is folded, as depicted by arrow 27, another edge 23 of the sheet 13 substantially meets the edge fold 17, as depicted by broken lines 25. When so folded minor flap 21 can be folded over major flap 29, as indicated by arrow 32 to form the sheet 13 into a sleeve. Printed media can thus be protected from environmental or handling damage.
Aligned holes, 30, 31 are generally provided to allow the user to store used protectors 11 in loose-leaf notebooks.
Alternatively to fold-sealing, permanent sealing such as by heat staking or ultrasonic welding is used. This sealing method may not be used with diacetate, however, due to inherent properties of the material. Moreover, such sealing does not allow alternate sealing and unsealing of a given sleeve.
Several weaknesses exist in such prior art embodiments. These types of protectors are often manufactured of diacetate. Diacetate is particularly brittle and, therefore, easy to tear. As a result, there is a tendency to develop cracks, particularly in the folds and around the holes, thus shortening the effective life expectancy of the protector.
Diacetate also has an affinity to absorb moisture from the environment. One result is that the sealing flap tends to curl and catch, causing handling and storage problems. Additionally, this causes the sleeves to become unaesthetic, and in extreme cases the sealing flap ceases to function as a useful seal.
Aesthetics can be particularly important if the sleeve is to be used to hold projection transparency media.
Other examples include sleeves and envelopes manufactured from clear plastic. These types are typically however, more expensive. Also, they are not as clear as sleeves made of diacetate, which, again, is of particular importance when used for projection media.
Hence, there is a need for improved printed media sleeves.